Short-Shaft Prosthesis: Specialists & Treatment Information

The philosophy behind short-shaft prostheses involves load-bearing close to the joint, which helps preserve bone mass as effectively as possible over the long term. Short-shaft prostheses were originally developed for young and active patients. In recent years, however, due to excellent results and several advantages over conventional prostheses, their use has increasingly expanded to include all other patient groups as well.

Artificial hip joints have been successfully implanted in Germany for many decades. The number of short-shaft prostheses has been rising steadily in recent years and already accounted for over 12 percent of all hip replacements in Germany in 2022. Across Europe, this type of prosthesis is gaining even greater acceptance. 

A short-shaft prosthesis is a specific type of hip prosthesis and belongs to the group of total hip endoprostheses (THA).

During the implantation of a short-shaft prosthesis, the hip socket in the pelvis is also replaced. What sets the short-shaft prosthesis apart, however, is that in the area of the femur, usually only a small portion of the femoral neck needs to be removed. The remaining femoral neck and the upper part of the femur serve to anchor the shorter prosthetic stem.

A short-shaft prosthesis, as an artificial hip joint, removes less bone material than other types of total hip replacement (THR) © Mathys, Switzerland

Treatment for hip osteoarthritis (coxarthrosis) typically begins with conservative measures. These include, for example,

• physical therapy,
• pain relievers, and
• weight loss, if necessary.

If these measures do not alleviate the symptoms, a hip replacement may be considered in cases of advanced hip osteoarthritis.

For most people, the artificial joint provides significant and long-lasting pain relief. It also restores mobility and range of motion.

Artificial hip joints have proven to be very durable. Approximately 95 percent of all hip replacements are still intact ten years after surgery. Between 85 and 90 percent are still in the body and functioning well even after more than 20 years.

The younger a patient is when receiving a hip replacement, the greater the likelihood that a revision surgery will be necessary later on. For young patients, it therefore makes sense to preserve as much bone as possible during the initial surgery with a view to a future prosthesis replacement. This can be achieved using a short-shaft prosthesis, which helps prevent problems during a subsequent revision surgery.

However, good bone quality is a prerequisite for using a short-shaft prosthesis. A short-shaft prosthesis has a smaller anchoring surface in the bone and places greater stress on it.

More natural stress distribution on the bone: The shorter stem and the fixation close to the joint improve the distribution of stress on the bone, leading to better preservation of the natural bone structure over the long term.

High stability: The special guide along the femoral neck ensures precise placement of the stem and high stability of the prosthesis.

Less tissue damage: The implantation of short-shaft prostheses generally requires a smaller incision and causes less tissue damage than conventional hip prostheses. Due to their rounded design, short-shaft prostheses are significantly better suited for use with minimally invasive approaches. This can lead to faster recovery, less bleeding, and less pain.

Improved mobility: Precise placement in line with the anatomy and more natural loading of the bone can improve hip joint mobility.

Lower risk of complications: Short-stem prostheses carry a lower risk of complications such as joint dislocation and fractures compared to traditional hip prostheses.

Shorter hospital stays: Due to less tissue damage and the resulting faster recovery, patients who receive short-shaft prostheses typically have shorter hospital stays.

The implantation of a short-stem prosthesis is performed under general or regional anesthesia. The surgery takes about 45 to 90 minutes.

With a short-shaft prosthesis, a minimally invasive approach to the hip is perfectly feasible, which is particularly gentle on the surrounding tissue. The surgeon makes a smaller incision on the front or front-lateral side of the hip joint.

Even more important than the small incision, however, is the preservation of the muscles and tendons surrounding the hip joint. This preservation of tissue often offers various advantages, such as

• less blood loss during surgery,
• less pain after surgery, and
• faster recovery.

First, the surgeon removes the femoral head and reams out the acetabulum. Next, they secure the prosthetic acetabulum to the pelvis and then the prosthetic stem (hip stem) to the femur. They then attach an artificial ball head. Due to its excellent long-term durability, this should be made of ceramic.

Short-stem prostheses are usually fixed “cementlessly,” meaning they are initially wedged into the upper, still-intact femur. This achieves what is known as primary stability. Over the weeks following the surgery, they integrate into the bone tissue, which further increases their stability. This is referred to as secondary stability.

Before closing the incision, the doctors take an X-ray to check the fit of the prosthesis.

This procedure ensures that the prosthesis is optimally positioned and that the surgery has the best possible chance of success.

For several years now, short-shaft prostheses with cemented fixation have also been available on the market for patients with poor bone quality. However, a final assessment of the safety and reliability of these cemented short-shaft prostheses is still pending at this time.

A short-shaft prosthesis is usually implanted cementlessly © Prof. Dr. med. Karl Philipp Kutzner

As a rule, full weight-bearing on the operated joint is possible immediately after the short-shaft prosthesis is implanted. Patients can usually stand up and take their first steps on the day of surgery. In the first few days after surgery, the physical therapy exercise program for the hip joint begins. Today, the hospital stay often lasts only about 2–3 days.

The treatment goals after surgery are

• for the patient to stand up and walk independently,
• to increase mobility, and
• climbing stairs.

Forearm crutches are usually used for this. Since most implants are cementless, impact loads and maximum-strength exercises should be avoided in particular during the first few weeks so as not to jeopardize proper osseointegration.

Any surgical procedure involving hip replacement carries general surgical risks. Anesthesia also contributes to these risks.

In rare cases, the use of an artificial hip can lead to fractures or cracks in the thighbone. With cementless prostheses, such as the short-shaft prosthesis, this risk is slightly increased. In this case, additional stabilization of the bone may be necessary, and a different type of prosthesis must be used. Stabilization can be achieved, for example, with wire loops, screws, or metal plates.

Muscle injuries or bleeding requiring a blood transfusion occur only very rarely during the surgical procedure.

In addition,

• inflammation,
• thrombosis, or
• pulmonary embolisms 

. Patients are given an antibiotic during surgery to prevent inflammation. In addition, in the weeks following surgery, they are prescribed anticoagulant medications in the form of injections or tablets. These are used to prevent thrombosis. 

Furthermore, there is a rare possibility that bone growth may occur around the artificial joint after the procedure. This bone formation restricts the mobility of the prosthesis. To prevent this from happening, patients take anti-inflammatory pain relievers for about two weeks, which also help prevent bone formation.

Furthermore, in the first few weeks after the procedure, there is a remote risk of dislocation—that is, the femoral head slipping out of the acetabulum. A dislocation is painful. In most cases, however, the femoral head can be repositioned without further surgery. In some cases, however, additional surgery is necessary. Since short-shaft prostheses are generally better able to replicate the anatomical conditions than conventional implants, the risk of such a dislocation is significantly lower. 

Nevertheless, it is advisable to exercise caution at first, avoid certain movements during the first six weeks after surgery, and use assistive devices for specific activities. This will be explained, practiced, and organized for you as part of your inpatient follow-up care.

Although short-shaft prostheses are still a relatively new type of prosthesis, we can now draw on over 10 years of experience and corresponding scientific data. In addition to the numerous advantages stemming from the shorter, rounder shape of these prostheses, the results from numerous implant registries worldwide demonstrate excellent outcomes for a wide variety of short-shaft prostheses. These are among the safest and most reliable implants in the first few years. The rate of reoperations or complications, such as loosening, is significantly lower than for conventional stem models.

The implantation and anchoring philosophy for short-stem prostheses differs from that of conventional hip stems. The surgeon’s experience with modern short-shaft prostheses therefore plays a crucial role for patients. Receiving thorough consultation from a short-shaft specialist prior to hip replacement contributes significantly to a successful procedure and an excellent surgical outcome.

In Germany, the short-shaft prosthesis has now become an established option for hip replacement in patients with good bone quality. It offers numerous advantages with manageable risks. It is expected that this type of prosthesis will become increasingly prevalent in the future. Since the technique and philosophy differ from those of other hip implants, extensive experience with short-stem prostheses is crucial. You should therefore consult a specialist in short-stem prostheses.